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At least 1,387 records · Page 77Linked to original sources
PubMed2004

Mutagenesis at the human tachykinin NK(2) receptor to define the binding site of a novel class of antagonists.

The pharmacological profile of novel antagonists endowed with high affinity for the human tachykinin NK(2) receptor is presented. MEN13918 (Ngamma[Nalpha[Nalpha(benzo[b]thiophen-2-yl)carbonyl]-1-aminocyclohexan-1-carboxy]-d-phenylalanyl]-3-cis-aminocyclohexan-1-carboxylic-acid-N-(1S,2R)-2-aminocyclohexyl)amide trifluoroacetate salt) and MEN14268 (Nalpha[Nalpha(benzo[b]thiophen-2-yl)carbonyl)-1-aminocyclopentane-1-carboxyl]-d-phenylalanine-N-[3(morpholin-4-yl)propyl]amide trifluoroacetate salt) were more potent in blocking neurokinin A (NKA, His-Lys-Thr-Asp-Ser-Phe-Val-Gly-Leu-Met-NH(2)) induced contraction in human, which induced greater contraction in human (pK(B) 9.1 and 8.3) than rat (pK(B) 6.8 and <6) urinary bladder smooth muscle preparation in vitro. In agreement with functional data, in membrane preparations of CHO cells stably expressing the human NK(2) receptors, both MEN13918 and MEN14268 potently inhibited the binding of agonist ([(125)I]NKA, K(i) 0.2 and 2.8 nM) and antagonist ([(3)H]nepadutant, K(i) 0.1 and 2.2 nM, [(3)H]SR48968 K(i) 0.4 and 6.9 nM) radioligands. Using site-directed mutagenesis and radioligands binding we identified six residues in the transmembrane (TM) helices that are critical determinants for the studied antagonists affinity. To visualize these experimental findings, we constructed a homology model based on the X-ray crystal structure of bovine rhodopsin and suggested a possible binding mode of these newly discovered antagonist ligands to the human tackykinin NK(2) receptor. Both MEN13918 and MEN14268 bind amongst TM4 (Cys167Gly), TM5 (Tyr206Ala), TM6 (Tyr266Ala, Phe270Ala), and TM7 (Tyr289Phe, Tyr289Thr). MEN13918 and MEN14268 diverging binding profile at Y289 mutations in TM7 (Tyr289Phe, Tyr289Thr) suggests a relation of their different chemical moieties with this residue. Moreover, the different influence on binding of these two ligands by mutations located deep along the inner side of TM6 (Phe270Ala, Tyr266Ala, Trp263Ala) indicates a nonequivalent positioning, although occupying the same binding crevice. Furthermore, binding data indicate the Ile202Phe mutation, which mimics the wild-type rat NK(2) receptor sequence, as a species selectivity determinant. In summary, data with mutant receptors describe, for these new tachykinin NK(2) receptor antagonists, a binding site which is partially overlapping either with that of the cyclized peptide antagonist nepadutant (cyclo-[[Asn(beta-d-GlcNAc)-Asp-Trp-Phe-Dpr-Leu]cyclo(2beta-5beta)] or the nonpeptide antagonist SR48968 ((S)-N-methyl-N[4-(4-acetylamino-4-phenylpiperidino)-2-(3,4-dichlorophenyl)butyl]benzamide).

Animals↗
PubMed2003

Magnetic resonance direct thrombus imaging.

As blood clots it goes through predictable stages that reflect the oxygenation state of hemoglobin within the red cells. One of these stages results in the formation of methemoglobin. This substance acts an endogenous contrast agent when imaged using a T1-weighted magnetic resonance sequence (Magnetic Resonance Direct Thrombus Imaging, MRDTI) - appearing as high signal. MRDTI can therefore be used to detect subacute thrombosis. This technique has been applied in a number of clinical settings arising as a result of thrombosis. Deep vein thrombosis and pulmonary embolism are both readily detected using MRDTI, providing a single imaging modality for the detection of venous thromboembolic disease. The technique is also effective in the peripheral arterial tree. Furthermore, thrombosis within vessel wall atherosclerosis is a marker of vulnerable plaque likely to produce symptoms. The MRDTI technique has thus proved useful in identifying complicated plaque in the carotid arteries in the setting of transient and permanent cerebral ischemia. MRDTI therefore holds promise as a technique that is capable of detecting high risk vessel wall disease prior to significant or permanent end organ damage. Because of the non-invasive nature of magnetic resonance imaging (MRI), application of MRDTI in the research setting for the monitoring of therapeutic interventions in a wide number of settings within vascular disease is very appealing.

Female↗
PubMed2001

Diversity among three novel groups of hyperthermophilic deep-sea Thermococcus species from three sites in the northeastern Pacific Ocean.

Eight new strains of deep-sea hyperthermophilic sulfur reducers were isolated from hydrothermal vent fields at 9 degrees 50'N East Pacific Rise (EPR) and at the Cleft and CoAxial segments along the Juan de Fuca Ridge (JdFR). 16S rRNA gene sequence analysis showed that each strain belongs to the genus Thermococcus. Restriction fragment length polymorphism patterns of the 16S/23S rRNA intergenic spacer region revealed that these isolates fell into three groups: those from the EPR, those from fluid and rock sources on the JdFR, and those isolated from Paralvinella spp. polychaete vent worms from the JdFR. The optimum-temperature specific growth rates and the temperature ranges for growth were significantly higher and broader for those strains isolated from worms relative to those isolated from low-temperature diffuse hydrothermal fluids. Furthermore, the worm-derived isolates generally produced a larger array of proteases and amylases based on zymogram analyses. The zymogram patterns also changed with growth temperature suggesting that these organisms alter their lytic protein suites in response to changes in temperature. This study suggests that there is significant phenotypic diversity in Thermococcus that is not apparent from their highly conserved 16S rRNA nucleotide sequences.

Journal Article↗
PubMed1999

Placement of deep brain stimulators into the subthalamic nucleus.

We present our technique for deep brain stimulation (DBS) of the subthalamic nucleus (STN) and include information which may be helpful in general DBS. With the patient in a stereotactic head frame, the anterior and posterior commissures are identified on SPGR-sequence magnetic resonance imaging (MRI). STN coordinates are based on a stereotactic brain atlas at 12 mm lateral, 2 mm posterior and 5 mm caudal to the midcommissural point. Surgical navigation software allows for planning of the trajectory. Electromyography is used to quantitatively measure tremor responses to macrostimulation. Permanent lead placement is confirmed with intraoperative fluoroscopy and postoperative MRI.

Brain Mapping↗
PubMed1997

Suppression of the expression of a pancreatic beta-cell form of the kinesin heavy chain by antisense oligonucleotides inhibits insulin secretion from primary cultures of mouse beta-cells.

Granular/vesicular transport is thought to be supported by microtubule-based force-generating adenosine triphosphatases such as kinesin. Kinesin is a motor molecule that has been well studied in brain and other neuronal tissues. Although vesicular transport is important for pancreatic beta-cell secretory activities, the role of kinesin in beta-cell function has not been investigated. It is hypothesized that kinesin functions as a translocator that associates with both microtubules and insulin-containing granules in beta-cells and transports the secretory granules from deep within the cytoplasm, where insulin is synthesized and processed, to the surface of beta-cells upon secretory stimulation. To test this hypothesis, a mouse beta-cell kinesin heavy chain complementary DNA was cloned and sequenced. Kinesin expression in primary cultures of mouse beta-cells then was selectively suppressed by antimouse beta-cell kinesin heavy chain antisense oligonucleotide treatment. Analysis of insulin secretion determined that the basal level of insulin secretion from the treated cells was decreased by 50%. Furthermore, glucose-stimulated insulin release from treated beta-cells was reduced by almost 70% after suppression of kinesin expression by antisense treatment. The findings from this study provide the first direct evidence that kinesin, a microtubule-based motor protein, plays an important role in insulin secretion.

Animals↗
PubMed2025

Multi-Omics and Integrative Analytics in Natural Products Discovery.

Natural products (NPs) have long been an essential source of new bioactive compounds for drug discovery; however, traditional methods for screening and isolating these compounds can be slow and often yield diminishing returns. Fortunately, advanced multi-omics and computational approaches present powerful solutions to these challenges. This review highlights innovative methodologies that integrate metabolomics, genomics, transcriptomics, and proteomics with bioinformatics and analytical chemistry to accelerate NP discovery. For instance, untargeted metabolomics platforms like high-resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS) and Global Natural Products Social (GNPS) molecular networking allow for comprehensive profiling of new compounds, while targeted isotope-labeling strategies enhance this process. Additionally, genome and metagenome mining tools such as antibiotics and secondary metabolite analysis shell (antiSMASH), Deep Biosynthetic Gene Cluster (DeepBGC), and Pipeline for Reconstructing Integrated Syntheses of Metabolites (PRISM) quickly identify biosynthetic gene clusters (BGCs) in both cultured and uncultured organisms, often using heterologous expression to validate products. Transcriptomic analyses, including RNA sequencing (RNA-seq), co-expression networks, and fluxomics, help clarify how pathways are regulated, while quantitative proteomics techniques like tandem mass tags/isobaric tags for relative and absolute quantitation (TMT/iTRAQ) and label-free methods, along with chemoproteomics approaches such as cellular thermal shift assay and thermal proteome profiling (TPP), uncover molecular targets and their mechanisms of action. This review also places significant emphasis on the role of artificial intelligence (AI) and machine learning (ML) in integrating multi-omics data, spanning activities from constructing gene-metabolite correlation networks to leveraging knowledge graphs and graph neural networks for data fusion and functional prediction. Finally, this review concludes by discussing the synergistic benefits of multi-omics for natural-product discovery, addressing current technical challenges, and exploring future directions toward high-throughput, intelligent data integration for next-generation NP research.

Biological Products↗
PubMed1985

[Vessels of the macro- and microcirculatory bed of the heart in the early developmental stage of acute myocardial infarct viewed by angioroentgenology, histology and electron microscopy].

A report is based on the investigation of the hearts of persons who died at an early ischemic (up to twenty-four hours) stage of the acute myocardial infarction studied under the light microscope (39 cases) and at the ultrastructural level (5 cases). An original technique of the combined filling of the macro- and microvascular bed was applied as well as the intravascular silver impregnation and special histologic methods for detection of the early lesions of cardiomyocytes were used in some cases. The interrelationship and sequence of lesions of the coronary arteries and vessels of the cardiac microcirculatory bed are shown. The lesions of microvessels bear mainly a secondary character and depend upon the duration of myocardial infarction, its dimensions and its deepness. The ultrastructural alterations of microvessels are characterized by the heterogeneity and dependence on the degree and character of the cardiomyocyte lesion. A morphological estimation of the compensatory-adaptive alterations in the cardiac vascular bed at the early stages of myocardial infarction development is given.

Angiocardiography↗
PubMed1985

Human aortic fibrolipid lesions. Progenitor lesions for fibrous plaques, exhibiting early formation of the cholesterol-rich core.

The early development of the lipid-rich core and other features of atherosclerotic fibrous plaques has been elucidated by examining discrete, small regions of raised intima in human aorta, which often bear a resemblance to both fatty streaks and fibrous plaques. Approximately one-fourth of small raised lesions (less than 16 sq mm of surface area) contained little or no stainable lipid, while three-fourths had a characteristic appearance, which included a superficial layer of foam cells, a core of noncrystalline and/or crystalline lipid, and a developed or developing collagenous cap. Total intimal volumes of the lipid-containing lesions, termed "fibrolipid lesions," ranged from 3 to 43 microliters, with the majority less than 16 microliters. Core lipid in the smallest lesions was located in the musculoelastic layer of the intima. In larger lesions the core extended luminally into the elastic hyperplastic layer, and cholesterol crystals were found more frequently. Total cholesterol concentration in fibrolipid lesions was similar to that in fatty streaks; however, the ratio of unesterified to total cholesterol was relatively high, similar to that found in fibrous plaques. It is concluded that 1) the formation of a lipid-rich core and cholesterol crystallization are early events in the development of many raised lesions; 2) the consistent association between the superficial layer of foam cells and the deep-lying lipid-rich core raises the possibility of an influence, possibly indirect, of foam-cell lipid metabolism on core formation; and 3) the fibrolipid lesion may represent one stage in a potential transitional morphologic sequence between fatty streak and fibrous plaque.

Adolescent↗
PubMed2005

Solution structure of the RIM1alpha PDZ domain in complex with an ELKS1b C-terminal peptide.

PDZ domains are widespread protein modules that commonly recognize C-terminal sequences of target proteins and help to organize macromolecular signaling complexes. These sequences usually bind in an extended conformation to relatively shallow grooves formed between a beta-strand and an alpha-helix in the corresponding PDZ domains. Because of this binding mode, many PDZ domains recognize primarily the C-terminal and the antepenultimate side-chains of the target protein, which commonly conform to motifs that have been categorized into different classes. However, an increasing number of PDZ domains have been found to exhibit unusual specificities. These include the PDZ domain of RIMs, which are large multidomain proteins that regulate neurotransmitter release and help to organize presynaptic active zones. The RIM PDZ domain binds to the C-terminal sequence of ELKS with a unique specificity that involves each of the four ELKS C-terminal residues. To elucidate the structural basis for this specificity, we have determined the 3D structure in solution of an RIM/ELKS C-terminal peptide complex using NMR spectroscopy. The structure shows that the RIM PDZ domain contains an unusually deep and narrow peptide-binding groove with an exquisite shape complementarity to the four ELKS C-terminal residues in their bound conformation. This groove is formed, in part, by a set of side-chains that is conserved selectively in RIM PDZ domains and that hence determines, at least in part, their unique specificity.

Adaptor Proteins, Signal Transducing↗
PubMed2007

Shewanella psychrophila sp. nov. and Shewanella piezotolerans sp. nov., isolated from west Pacific deep-sea sediment.

Two Shewanella-like bacterial strains, WP2(T) and WP3(T), which were isolated from west Pacific deep-sea sediment, were studied to determine their taxonomic position. Cells of the two bacteria were facultatively anaerobic, Gram-negative rods and motile by means of a single polar flagellum. Strain WP2(T) was psychrophilic, growing optimally at about 10-15 degrees C, whereas strain WP3(T) was psychrotolerant, growing optimally at 15-20 degrees C. The two strains grew in the pressure range 0.1-50 MPa, with optimal growth at 20 MPa. Strain WP3(T) was able to use nitrate, fumarate, trimethylamine N-oxide (TMAO), DMSO and insoluble Fe(III) as terminal electron acceptors during anaerobic growth, whereas strain WP2(T) was able to use only nitrate, TMAO and DMSO. The 16S rRNA gene sequences of strains WP2(T) and WP3(T) were 97 % identical, and showed highest similarity (97 %) to those of Shewanella fidelis KMM 3589 and Shewanella benthica ATCC 43992(T), respectively. The gyrB gene sequences of strains WP2(T)and WP3 (T) were also determined, and showed highest similarity to those of Shewanella violacea JCM 10179(T) (90 %) and Shewanella sairae SM2-1(T) (87 %), respectively. Contrary to the 16S rRNA gene sequence results, the phylogeny based on gyrB gene sequence analysis placed strain WP2(T), S. violacea and S. benthica in one group, while strain WP3(T) grouped with S. fidelis and S. sairae. DNA-DNA hybridization experiments supported the placement of strain WP2(T) with S. violacea and S. benthica. Phylogenetic evidence, together with DNA-DNA relatedness and phenotypic characteristics, indicated that the two new strains represented two novel deep-sea Shewanella species. The names Shewanella psychrophila sp. nov. (type strain WP2(T)=JCM 13876(T)=CGMCC 1.6159(T)) and Shewanella piezotolerans (type strain WP3(T)=JCM 13877(T)=CGMCC 1.6160(T)) are proposed.

Bacterial Typing Techniques↗
PubMed2005

The role of classic spin echo and FLAIR sequences for the evaluation of myelination in MR imaging.

PURPOSE: The aim of this study was to assess the features of the normal brain development in terms of myelination in infants and young children on fluid-attenuated inversion recovery (FLAIR) magnetic resonance (MR) imaging, and to determine if FLAIR imaging is superior to spin echo MR sequences. MATERIALS AND METHODS: T1-weighted (T1W) fast spin echo T2-weighted (FSE T2W), and FLAIR images were obtained in 76 pediatric patients between the ages of 0 and 48 months, on a 1 Tesla MR unit. On these images, the signal intensities of 16 different white matter regions were compared to those of adjacent gray matter, and for each brain region. Comparisons between the gray and white matter signal intensities were scored by the consensus of two radiologists on a scale of -1 to +1 for each patient. RESULTS: In the first 6 months, hypointense white matter signal intensity changed to hyperintensity on T1W images. After the first 6 months, white matter progressed from hyperintense to hypointense on T2W images. Except for the cerebral white matter, FLAIR images showed the same signal transition, though slightly later than what was seen on T2W images. The deep cerebral white matter, which was hypointense on birth, became hyperintense early in the first several months of life, and finally, reconverted to hypointense during the second year of life on FLAIR images. CONCLUSION: Myelination, which is an indicator of brain maturation, was successfully demonstrated both in classic spin echo sequences and on FLAIR images. These imaging techniques are an essential component of routine MR imaging of the dating of and differentiation between normal and pathological brain development.

Brain↗
PubMed1993

Refined structure of bovine carbonic anhydrase III at 2.0 A resolution.

The three-dimensional structure of bovine carbonic anhydrase III (BCA III) from red skeletal muscle cells has been determined by molecular replacement methods. The structure has been refined at 2.0 A resolution by both constrained and restrained structure-factor least squares refinement. The current crystallographic R-value is 19.2% and 121 solvent molecules have so far been found associated with the protein. The structure is highly similar to the refined structure of human carbonic anhydrase II. Some differences in amino acid sequence and structure between the two isoenzymes are discussed. In BCA III, Lys 64 and Arg 91 (His 64 and Ile 91 in HCA II) are both pointing out from the active site cavity forming salt bridges with Glu 4 and Asp 72 (His 4 and Asp 72 in HCA II), respectively. However, Arg 67 and Phe 198 (Asn 67 and Leu 198 in HCA II) are oriented towards the zinc ion and significantly reduce the volume of the active site cavity. Phe 198 particularly reduces the size of the substrate binding region at the "deep water" position at the bottom of the cavity and we suggest that this is one of the major reasons for the differences in catalytic properties of isoenzyme III as compared to isozyme II.

Amino Acid Sequence↗
PubMed1996

Combinatorial peptide libraries: robotic synthesis and analysis by nuclear magnetic resonance, mass spectrometry, tandem mass spectrometry, and high-performance capillary electrophoresis techniques.

Combinatorial peptide libraries are a new source of compounds from which a large number of pharmacological leads will emerge in the next few years. A large body of literature shows that this approach is of considerable interest in many areas of biological sciences for the search of enzyme substrates and inhibitors, of receptor agonists or antagonists, or of antigen sequences. Nevertheless, the analytical investigation of such complex mixtures as libraries which contain up to millions of individual molecules is still poorly documented. In this work, we present analytical solutions for their characterization. NMR and tandem mass spectrometry (MS/MS) can provide an in deep description of any type of combinatorial libraries, while MS and high-performance capillary electrophoresis can bring a rapid and overall information at the routine level, sufficient to ensure a first assessment of their composition. MS in the fast atom bombardment mode was used to describe the libraries O1X2X3X4X5 or O1X2X3X4 (Oi and Xi are fixed and random residue in position i, respectively). Advantage was taken of the high proton affinity of arginine and of its induction of charge remote fragmentation to interpret the MS spectra of whole libraries and neutral losses (MS/MS) in the model sublibraries ArgGlyX3X4 and NipValX3X4 (Nip,4-nitrophenylalanine). Two-dimensional NMR allowed the incorporation of the individual residues during synthesis to be tested in 24 sublibraries O1X2X3X4. While from the pharmacological point of view, impressive discoveries made with combinatorial peptide libraries have already been reported, our results show that they should be complemented by appropriate analytical tools, crucial for the proper characterization and exploitation of these libraries.

Amino Acid Sequence↗
PubMed1996

Coexistence of phycoerythrin and a chlorophyll a/b antenna in a marine prokaryote.

Prochlorococcus marinus CCMP 1375, a ubiquitous and ecologically important marine prochlorophyte, was bound to possess functional genes coding for the alpha and beta subunits of a phycobiliprotein. The latter is similar to phycoerythrins (PE) from marine Synechococcus cyanobacteria and bind a phycourobilin-like pigment as the major chromophore. However, differences in the sequences of the alpha and beta chains compared with known PE subunits and the presence of a single bilin attachment site on the alpha subunit designate it as a novel PE type, which we propose naming PE-III. P. marinus is the sole prokaryotic organisms known so far that contains chlorophylls a and b as well as phycobilins. These data strongly suggest that the common ancestor of prochlorophytes and the Synechococcus cyanobacteria contained phycobilins. Flow cytometric data from the tropical Pacific Ocean provide evidence that deep populations of Prochlorococcus possess low amounts of a PE-like pigment, which could serve either in light harvesting or nitrogen storage or both.

Amino Acid Sequence↗
PubMed2005

Bacterial community composition in Lake Tanganyika: vertical and horizontal heterogeneity.

Vertical and latitudinal differences in bacterial community composition (BCC) in Lake Tanganyika were studied during the dry season of 2002 by means of denaturing gradient gel electrophoresis analysis of PCR-amplified 16S RNA fragments. Dominant bands were sequenced and identified as members of the Cyanobacteria, Actinobacteria, Nitrospirae, green nonsulfur bacteria, and Firmicutes divisions and the Gamma- and Deltaproteobacteria subdivisions. The BCC in the lake displayed both vertical and latitudinal variation. Vertical changes in BCC were related to the thermal water column stratification, which influences oxygen and nutrient concentrations. Latitudinal variation was related to upwelling of deep water and increased primary production in the south of the lake. The number of bands per sample increased with bacterial production in the epilimnion of the lake, suggesting a positive diversity-productivity relationship.

Bacteria↗
PubMed2006

A two-tier approach to mutation detection in the COL4A5 gene for Alport syndrome.

About 85% of Alport syndrome is an X-linked semi-dominant condition caused by mutations in the collagen gene, COL4A5. The large size and high GC content of this gene have presented diagnostic laboratories with problems in identifying mutations with greater than about a 50% success rate since the gene was first cloned 16 years ago. An RNA based approach is adopted here for a first pass mutation scanning coupled with more traditional exon-by-exon screening to increase the rate of mutation identification. Twenty-one mutations were identified in twenty-five patients with clear Alport syndrome including four gross deletions, two deep intronic mutations, three frameshifts, three splice site mutations, eight missense mutations and one inframe deletion.

Base Sequence↗
PubMed1992

A single nonpolar residue in the deep pore of related K+ channels acts as a K+:Rb+ conductance switch.

K+ and Rb+ conductances (GK+ and GRb+) were investigated in two delayed rectifier K+ channels (Kv2.1 and Kv3.1) cloned from rat brain and a chimera (CHM) of the two channels formed by replacing the putative pore region of Kv2.1 with that of Kv3.1. CHM displayed ion conduction properties which resembled Kv3.1. In CHM, GK+ was three times greater than that of Kv2.1 and GRb+/GK+ = 0.3 (compared with 1.5 and 0.7, respectively, in Kv2.1 and Kv3.1). A point mutation in CHM L374V, which restored 374 to its Kv2.1 identity, switched the K+/Rb+ conductance profiles so that GK+ was reduced fourfold, GRb+ was increased twofold, and GRb+/GK+ = 2.8. Quantitative restoration of the Kv2.1 K+/Rb+ profiles, however, required simultaneous point mutations at three nonadjacent residues suggesting the possibility of interactions between residues within the pore. The importance of leucine at position 374 was verified when reciprocal changes in K+/Rb+ conductances were produced by the mutation of V374L in Kv2.1 (GK+ was increased threefold, GRb+ was decreased threefold, and GRb+/GK+ = 0.2). We conclude that position 374 is responsible for differences in GK+ and GRb+ between Kv2.1 and Kv3.1 and, given its location near residues critical for block by internal tetraethylammonium, may be part of a cation binding site deep within the pore.

Amino Acid Sequence↗
PubMed1996

Submergence enhances expression of a gene encoding 1-aminocyclopropane-1-carboxylate oxidase in deepwater rice.

Partial submergence greatly stimulates internodal growth in deep water rice (Oryza sativa L.). Previous work has shown that the effect of submergence is, at least in part, mediated by ethylene, which accumulates in the air spaces of submerged internodes. To investigate the expression of the genes encoding ethylene biosynthetic enzymes during accelerated growth of deep water rice, we cloned a 1-aminocyclopropane-1-carboxylate (ACC) oxidase cDNA (OS-ACO1) from internodes of submerged plants and measured the activity of the enzyme in tissue extracts with an improved assay. We found an increase in ACC oxidase mRNA levels and enzyme activity after 4 to 24 h of submergence. Thus, it is likely that ethylene biosynthesis in internodes of deep water rice is controlled, at least in part, at the level of ACC oxidase.

Amino Acid Oxidoreductases↗